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clocksource/qcom-timer: Convert to hotplug state machine 

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.295486558@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Richard Cochran 2016-07-13 17:16:43 +00:00 committed by Ingo Molnar
parent 31e8e5db88
commit b04041655d
2 changed files with 12 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
drivers/clocksource/qcom-timer.c
View File

@ -105,9 +105,9 @@ static struct clocksource msm_clocksource = {
static int msm_timer_irq;
static int msm_timer_has_ppi;
static int msm_local_timer_setup(struct clock_event_device *evt)
static int msm_local_timer_starting_cpu(unsigned int cpu)
{
int cpu = smp_processor_id();
struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
int err;
evt->irq = msm_timer_irq;
@ -135,35 +135,15 @@ static int msm_local_timer_setup(struct clock_event_device *evt)
return 0;
}
static void msm_local_timer_stop(struct clock_event_device *evt)
static int msm_local_timer_dying_cpu(unsigned int cpu)
{
struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
evt->set_state_shutdown(evt);
disable_percpu_irq(evt->irq);
return 0;
}
static int msm_timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
/*
* Grab cpu pointer in each case to avoid spurious
* preemptible warnings
*/
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
msm_local_timer_setup(this_cpu_ptr(msm_evt));
break;
case CPU_DYING:
msm_local_timer_stop(this_cpu_ptr(msm_evt));
break;
}
return NOTIFY_OK;
}
static struct notifier_block msm_timer_cpu_nb = {
.notifier_call = msm_timer_cpu_notify,
};
static u64 notrace msm_sched_clock_read(void)
{
return msm_clocksource.read(&msm_clocksource);
@ -200,14 +180,15 @@ static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
if (res) {
pr_err("request_percpu_irq failed\n");
} else {
res = register_cpu_notifier(&msm_timer_cpu_nb);
/* Install and invoke hotplug callbacks */
res = cpuhp_setup_state(CPUHP_AP_QCOM_TIMER_STARTING,
"AP_QCOM_TIMER_STARTING",
msm_local_timer_starting_cpu,
msm_local_timer_dying_cpu);
if (res) {
free_percpu_irq(irq, msm_evt);
goto err;
}
/* Immediately configure the timer on the boot CPU */
msm_local_timer_setup(raw_cpu_ptr(msm_evt));
}
err:

1
include/linux/cpuhotplug.h
View File

@ -39,6 +39,7 @@ enum cpuhp_state {
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
CPUHP_AP_DUMMY_TIMER_STARTING,
CPUHP_AP_METAG_TIMER_STARTING,
CPUHP_AP_QCOM_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,